1. Field of the invention
The invention concerns a re-usable theft-resistant package for the self-service merchandizing of goods, comprising a cover retained by a lock operated mechanically and electromagnetically by a key device.
2. Description of the prior art
The invention has been conceived to take into account special features of self-service retailing, as practised notably in supermarkets and hypermarkets, where goods and merchandize are offered for sale to customers in different departments, the customers themselves selecting the goods and merchandize they wish to purchase and completing the purchase at a checkout where payment is made. This merchandizing method offers the advantage of a substantial increase in the volume of sales per employee and of giving the customer the impression of freedom of choice. On the other hand, its major disadvantage is that it facilitates theft, especially of small articles which can be easily hidden when passing through the checkouts.
To reduce this type of theft, sometimes referred to as "unknown mark-down", it is common practice to offer small articles for sale in packaging consisting of a backing sheet of cardboard or similar material covered with a transparent plastics film shaped to provide a housing for the article. This type of package is often referred to as a "blister pack". In practice, the backing sheet is substantially rectangular, with suspension means in the form of an eyelet or hook formed in an extension on one of the shorter sides of the rectangle, this rectangle often having dimensions larger than those of an ordinary garment pocket.
These types of merchandizing package are non-re-usable, however. They must be easily destroyed to enable purchasers to gain access to the articles without using special tools. When the articles enclosed are of intrinsically high value or constitute a special attraction for customers in reduced circumstances, these non-re-usable packages do not offer the store sufficient security, as they can be opened to take out the articles contained in them and then thrown away and the article hidden, at a sufficient distance from the checkouts for the attempted theft to go unseen. Thus it is very rare for watches or prerecorded magnetic tape cassettes to be offered for sale on a self-service basis, at least in non-specialist stores where surveillance is less active.
There have been produced and used packages of the same general form as the non-re-usable packages, but re-usable in that they have a cover which is retained by a lock which is opened using a key device at the checkout. In principle, this arrangement represents a significant improvement in security against the type of theft just described. It will be clear that the re-usable device may be more expensive than the disposable packaging.
However, the degree of security obtained is directly proportional to the resistance of the lock. A conventional key-operated lock would be of no utility since the need for quick opening at any checkout would require that all locks correspond to the same key and that the key be produced in large numbers. It would not be possible to prevent the illicit copying of keys.
In one known arrangement, the lock consists of an electromagnetic device similar to an electric striker box. The key device at the checkouts comprises an electrical power source to operate the lock. To prevent fraudulent opening, the parts which connect the key device to the lock of the package are of unusual shape, in particular to render access to the terminals on the package difficult. Also, the male part of the connector carried by the key device is adapted to push back an auxiliary mechanical lock which prevents operation of the electromagnetic lock.
This arrangement, conceived to make fraudulent opening highly difficult, has proven in use to be susceptible to forcing. The force which the moving armature of an electric striker box can withstand is extremely limited, which results in the need for gearing down and renders the closure highly sensitive to impact. Further, the auxiliary mechanical lock may be operated from the outside, by inserting a pointed instrument into the housing formed in the package to permit entry of the male part of the connector carried by the key device. As a result, the package may be opened.
The object of the invention is a theft-resistant package combining electromagnetic and mechanical opening and which does not features these disadvantages.